A release film is a film which facilitates handling and transport of a product and can be easily separated, and has been utilized for various uses. For example, the release film may be used as a carrier film for an adhesive film. In this case, when a plurality of release films is used, there may occur a phenomenon in that an adhesive is lifted up or a problem in that an adhesive is transferred to the release film, depending on each difference in release strength. Therefore, there is a need for a verification means for selecting a release film having peeling stability in which a phenomenon in which an adhesive is lifted up does not occur because release strengths among a plurality of release films are balanced as a carrier for an adhesive film.